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Control of immunoactive inhibin production by human granulosa cells
Author(s) -
Hillier S. G.,
Wickings E. J.,
Illingworth P. I.,
Yong E. L.,
Reichert Jr L. E.,
Baird D. T.,
McNeilly A. S.
Publication year - 1991
Publication title -
clinical endocrinology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.055
H-Index - 147
eISSN - 1365-2265
pISSN - 0300-0664
DOI - 10.1111/j.1365-2265.1991.tb03499.x
Subject(s) - medicine , endocrinology , granulosa cell , follicular phase , luteinizing hormone , ovarian follicle , testosterone (patch) , biology , ovary , follicle stimulating hormone , hormone , gonadotropin , antral follicle , chemistry
Summary. objective The aim was to determine the relation between stage of antral follicular development and granulosa cell production of immunoactive inhibin. design Primary granulosa cell cultures In serum‐free Medium 199 were Incubated at 37°C for 96 hours with a change of medium at 48 hours. Inhibin and steroid levels in culture medium were determined by radlolmmunoassay. The Inhibin assay was based on the N‐terminal 1–26 amino acid sequence of the α‐chain of porcine 32 kDa inhibin using plα 1–26 ‐GLY 27 ‐TYR 28 as the immunogen, tracer and standard.patients Granulosa cells were obtained from the ovaries of women with regular menstrual cycles undergoing hysterectomy with unilateral or bilateral oophorectomy to treat non‐malignant gynaecological disease. results Basal production of immunoactive Inhibin by granulosa cells from presumptive preovulatory follicles (> 15 mm diameter) was 5–13 times higher than that by granulosa cells from immature (< 10 mm diameter) or intermediately mature (10–15 mm diameter) follicles. Basal production of progesterone and oestradlol followed a qualitatively similar pattern, establishing a positive relation between functional granulosa cell maturity and inhibin production. Treatment of granulosa cell cultures from Immature follicles with follicle‐stimulating hormone (FSH), but not luteinizing hormone (LH), increased inhibin production, time and dose dependently. FSH, but not LH, also brought about similar Increases in steroid hormone synthesis by granulosa cells from immature follicles. The stimulatory effect of FSH on granulosa cell inhibin production was augmented at least twofold by the presence of testosterone or 5α‐dihydrotestosterone (1.0 μmol/I) but was unaffected by oestradiol. Granulosa cells from intermediately mature follicles undertook variable degrees of both FSH and LH‐responsive inhibin production which generally corresponded with gonadotrophin‐responsive steroid production. Granulosa cells from presumptive preovulatory follicles showed inconsistent inhibin responses to FSH. However, LH caused marked (at least twofold) Increases in inhibin production, paralleling LH‐responsive steroid production. conclusion These results show that for human beings, granulosa cell capacity to produce immunoactive inhibin in vitro increases with follicular maturity. FSH, but not LH, stimulates inhibin production by immature granulosa cells and this response to FSH Is subject to modulation by androgen. During preovulatory follicular development, production of inhibin, like steroids, becomes increasingly responsive to LH. Such a development‐related pattern of granulosa cell inhibin production helps explain how, post‐ovulation, the corpus luteum is able to secrete inhibin as well as steroids. It is also compatible with the concept that locally produced inhibin could participate In the paracrine control of follicular development during the human menstrual cycle.